Pseudo-dynamic approach of seismic active earth pressure behind retaining wall

Abstract

Abstract. Knowledge of seismic active earth pressure behind rigid retaining wall is very important in the design of retaining wall in earthquake prone region. Commonly used Mononobe-Okabe method considers pseudo-static approach, which gives the linear distribution of seismic earth pressure in an approximate way. In this paper, the pseudo-dynamic method is used to compute the distribution of seismic active earth pressure on a rigid retaining wall supporting cohesionless backfill in more realistic manner by considering time and phase difference within the backfill. Planar rupture surface is considered in the analysis. Effects of a wide range of parameters like wall friction angle, soil friction angle, shear wave velocity, primary wave velocity and horizontal and vertical seismic accelerations on seismic active earth pressure have been studied. Results are provided in tabular and graphical non-dimensional form with a comparison to pseudo-static method to highlight the realistic non-linearity of seismic active earth pressures distribution.

Seismic stability of reinforced-soil wall by pseudo-dynamic method

“…As proposed by Steedman and Zeng (1990), the phase difference due to finite shear wave propagation through a reinforced soil wall can be considered using a relatively new method, called the pseudo-dynamic method in this paper. Recently, Choudhury and Nimbalkar (2006) proposed a theory to compute the seismic active earth pressure by pseudodynamic method by considering both the shear and the primary waves propagating through the soil with variation in time by considering harmonic horizontal and vertical seismic accelerations. Choudhury and Nimbalkar (2005) also developed the theory to estimate the seismic passive earth pressure using the pseudo-dynamic approach.…”

Reply to the discussion by Greco on “Seismic active earth pressure behind a nonvertical retaining wall using pseudo-dynamic analysis”Appears in Canadian Geotechnical Journal, 45(12): 1795–1797.

“…However, the objective of my paper was not to explore the critical condition but rather to study the application of the pseudo-dynamic approach to determine the seismic active thrust on a nonvertical cantilever retaining wall. The Mononobe-Okabe method (Kramer 1996) and the method of Choudhury and Nimbalkar (2006) considered Q v acting in a vertically upward direction to report the magnitude of K ae . Keeping this in view, the direction of Q v was considered the same in the analysis in my paper just to compare the existing values in the literature, and therefore a systematic search of the direction of Q v under the critical condition was beyond the scope of my study.…”

Evaluation of Unsaturated Layer Effect on Seismic Analysis of Unbraced Sheet Pile Wall

“…But the similar consideration of both the soil and the wall inertia effects for seismic design of a retaining wall under the passive condition of earth pressure is still scarce. Recently, based on the dynamic method proposed by Steedman and Zeng [14], Zeng and Steedman [15], Choudhury and Nimbalkar [16] for the active earth pressure condition, Choudhury and Nimbalkar [17] [18] had proposed the theory to compute the seismic passive earth pressure by dynamic method by considering both the shear and the primary waves propagating through the soil with a time variation. But the analysis did not consider the effect of the amplification and the wall inertia in the seismic design of the wall, hence leading to an incomplete analysis for design purpose of the wall.…”